CD1--the pathology perspective

Gastrointestinal spindle cell tumor of the rumen with metastasis to the liver in a goat

Many neoplasms have been reported in goats; however, neoplasia of the rumen is rarely reported. A 9-y-old castrated male pygmy goat was presented with a history of respiratory stertor, fever, and anorexia. A respiratory diagnostic work-up including skull and thorax radiographs and endoscopy revealed minor enlargement of the arytenoids but no other abnormal findings. After a month of little improvement on symptomatic treatment and worsening general health, the goat was euthanized. On autopsy, the forestomachs, liver, spleen, diaphragm, and the ventral and lateral aspects of the cranial third of the walls of the peritoneal cavity were adhered to one another by fibrinous and fibrous adhesions. Numerous firm, white, up to 2 cm diameter nodules were found throughout the liver. A large sessile mass extended from the rumen wall into the lumen. The rumen mass was a gastrointestinal stromal tumor with metastasis to the liver.

Distribution of immune response cells in the pelvic urethra and the prepuce of rams

The pathogens of the reproductive system in the male can penetrate and establish by ascending route, from to the prepuce to the urethra, accessory glands, epididymis and testicles. The aim of this paper is determine the distribution and number of cells involved in the immune response in prepuce and pelvic urethra of rams, without apparent clinical alterations in testicle, epididymis and prepuce. The distribution of some of the cells involved in the immune response at the level of the prepuce and the pelvic urethra was quantified in four one-year-old rams seronegative for B. ovis and A. seminis and without apparent lesions in the testicles, the epididymis, and the prepuce. At the moment of slaughter, samples were taken from the preputial fornix and the pelvic urethra and placed in 10% formalin and under freezing conditions. CD4, CD8, WC1, CD45RO, CD14 and CD1b cells were demonstrated by immunohistochemistry, and immunoglobulin-containing cells (ICC) of the IgA, IgG and IgM classes were demonstrated by immunofluorescence. The labeled cells present in the mucosa of both organs were counted with an image analyzer. The total number of cells was compared between both tissues and differentially between the epithelium and the connective tissue of the mucosa. Significant differences were found in the total number of CD4, CD45RO, and WC1 lymphocytes, in CD14 macrophages, and CD1b dendritic cells, with mean values being greater in the fornix than in the urethra (p<0.05) in all cases. Only dendritic cells were found in the prepuce. No differences were found in the number of CD8 lymphocytes between both organs. The ratio between each cell type in the connective and the intraepithelial tissues and between organs was 10/1 for CD4 in the fornix (p<0.05), against 7/1 in the urethra (p<0.05), while CD8 had a 1/1 distribution in both mucosae. The WC1 ratio was 5/1 in both mucosae (p<0.05). CD45RO labeling was 19/1 in the prepuce (p<0.05) and 1/1 in the urethra. IgA-containing cells did not show differences in the total number of cells in both tissues. In the urethra, no IgG-containing cells were observed and IgM-containing cells were scarce; in contrast, both cell types were present in the prepuce, in amounts greater than in the urethra (p<0.05). IgA-, IgG-, and IgM-containing cells were located in both organs in the mucosal connective tissue. The presence of antigen-presenting cells, macrophages, and dendritic cells, as well as of lymphocytes CD4, CD8 TCR γδ (WC1), IgA-, IgG and IgM positive cells, and CD45RO cells suggests that both mucosae may behave as inductive and effector sites for the mucosal immune response.

Experimental African trypanosomiasis: lack of effective CD1d-restricted antigen presentation

BALB/c mice are highly susceptible to African trypanosomiasis, whereas C57BL/6 mice are relatively resistant. Other investigators have reported that the synthesis of IgG antibodies to purified membrane form of variant surface glycoprotein (mfVSG) of Trypanosoma brucei is CD1 restricted. In this study, we examine the role of the CD1d/NKT cell pathway in susceptibility and resistance of mice to infection by African trypanosomes. Administration of anti-CD1d antibodies to Trypanosoma congolense-infected BALB/c mice neither affects the parasitemia nor the survival time. Correspondingly, CD1d(-/-) and CD1d(+/+) BALB/c mice infected with T. congolense or T. brucei show no differences in either parasitaemia or survival time. The course of disease in relative resistant C57BL/6 mice infected with T. congolense is also not affected by the absence of CD1d. Parasitaemia, survival time, and plasma levels of IgG2a and IgG3 parasite-specific antibodies in infected CD1d(-/-) C57BL/6 are not different from those of infected CD1d(+/+) C57BL/6 mice. We conclude that CD1d-restricted immune responses do not play an important role in susceptibility/resistance of mice infected with virulent African trypanosomes. We speculate that virulent trypanosomes have an evasion mechanism that prevents the induction of a parasite-specific, CD1d-restricted immune response by the host.

CD1d expression on hemopoietic cells promotes CD4+ Th1 response in coxsackievirus B3 induced myocarditis

Coxsackievirus B3 induced murine myocarditis depends upon CD1d expression and upon a population of CD1d-restricted Vgamma4+ T cells. Infection upregulates CD1d expression in CD4+ T cells. Bone marrow chimeras were made between BALB/c and BALB/c CD1d-/- mice and showed that CD1d expression in either hemopoietic and non-hemopoietic cells induces myocarditis, although CD1d expression on hemopoietic cells was more effective in increasing Vgamma4+ cell numbers and activation, and CD4+ IFNgamma+ cell response than CD1d expression on non-hemopoietic cells. Co-culture of enriched CD4+ cells from infected CD1d-/- and BALB/c mice with Vgamma4+ T cells demonstrated that the Vgamma4+ cells bias the CD4+ cell response to the Th1 phenotype through CD1d. Anti-CD1d antibody effectively blocked promotion of IFNgamma expression by the CD4+ cell population. These results show that Vgamma4+ cells modulate developing adaptive immunity through recognition of CD1d on CD4+ T cells, and that this interaction, more than Vgamma4+ cell interaction with infected cardiocytes, determines pathogenicity.

Immunophenotype and functional properties of feline dendritic cells derived from blood and bone marrow

Dendritic cells (DCs) are a heterogeneous population of cells of fundamental importance in initiating innate as well as specific immune responses. The identity and function of DCs in the cat are unknown, although they are likely pivotal in the response to infection. In this study, feline DCs were derived by 3-10-day culture of adherent blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMCs) in the presence of IL 4 and GM-CSF. BMMC consistently yielded a greater number of DCs than PBMC, and there were fewer macrophages than DC from both compartments. DCs expressed a distinct constellation of surface molecules, which included CD1a, CD1b, and CD1c, CD11b, CD14, and 2-3-fold higher levels of MHC class I and II molecules than co-cultured macrophages or fresh blood monocytes. DCs displayed typical cytoplasmic processes, limited non-specific esterase activity, and acquired antigen by phagocytosis, pinocytosis, and binding to specific receptors. Cytokine-exposed cells induced proliferation of allogeneic lymphocytes. Thus, the cells derived by these culture conditions had markers and functions analogous to immature myeloid DCs. Availability of feline DCs will enable investigation of their role in infectious disease and their potential therapeutic application.